The hypothetical scenario is given as follows.
- Yesterday night I played game and intentionally did not do the homework. I did not forget for sure. :-)
- This morning the teacher asked me and I want to pretend to regret what I did.
From this scenario, I want to say something that makes use of ~てしまいました grammar.
宿題を[the て form of しない]しまいました。
What is the て form of しない ?